WAMEAKUMA

The Kaptlrnrin Formation The Kapthurin Formation is exposed west of

Lake Baringo, Kenya, and forms the Middle

Hill 2002 and refirences therein). Hominid remains have been rccovcftd from sediments bracketed by

Pleistoctne portionofthe~mHillssequence(see

the Pumice Tuffmcmbcr(K2) and the 'Grcy Tuff;' now dated by the 'OArPAr method to between 509 9 ka and 543 f 4 ka @em and McBrearty 2002; Wood 1999). Archaeological sites arc a U r i i l e the Acheulian, MSA and possibly Sangoan and Faunsrmth. * TheseoccurwithintheMiddleSihsand Gravels member (K3) and tbc overlying Bddcd Tuff member (K4), the latter a complex of tufibous de positsandintercalatcd scdiment(Tal1m 1976,1978, Cornelissen et al. 1990; McBrearty et d. 1996; McBrearty 1999; Tryon and McBrearty 2002~). Tcphmstxatigraphic correlatim and a sequence of '"ArPAr dates on Wand lava document the tempo- ral succession and age of these sites. This work has demonstrated the complexity of the Acheulien-MSA aansitioq with intmtmtified Achwlian and MSA sites,andshown~thistransitimwithiatheBaringo basin had by -285 Ica (TIYOU and McBrtarty 200% b i n 0 and McBreglty 2002).

RiwarcbaeologicalresearchmtheKapthurin Formation focused on exposum north of the Ndau River, witb only cursory exambation of more south- erly areas (McBrearty a al. 1996566-570). slpvey in 2001 focused on -40 kmf of additional geologi- cally mapped Kapthurin Formation sediments (Martyn 1 969; Tallon 1976) soutb of the Ndau River, an area informally designated the "suuthem" Kapthurin Formation.

Middle Pleistocene shes from the 'southern" Kapthurin Formation of Kenya

Christian A. Tryon University of Connecticut Department of Anthropology

Storrs, Connecticut, 06269, USA E-mail: christian.tryon@uconn.edu

BOX U-2176

Introduction Fossil and genetic evidence is consistent with

an Afiican origin for Homo sapiens during the Mid- dle Pleistocene (Stringer and An- 1988; Howell 1999; M c B W and Brooks 2000). One notable feature of the Afican Middle Pleistocene archaeo-

Industrial Complex and its replacement by diverse industries of the Middle Stone Age (MSA) (Isaac 1982; Clark 1994; McBrearty 2001). Evidence for a suite of novel behaviors that characterize - modern& recentforagcrsisassociatcdwithh4iddlePkistocene MSA sites, and the earliest Homo sapiens fossils arc found with MSA artifacts (see Clark 1988; Deacoo and Deacon 1999; McBrearty and Brooks 2000 for recent summaries).

These data suggest significant behavioral changes during the Middle Pleistocene by hominids employing MSA technology. Previously, only broad contrasts between Acheulian and MSA sites were possible due to a lack of Afican sites with a well- preserved, dated, continuous sedimentary and ar- chaeological record spanning the Acheulian-MSA transition (Clark 1982; Wendorf er d. 1994). By examining this transition in detail, we may begin to understand the causes underlying hominid behavioral

to test recent hypotheses comlating the advent of the MSA with hominid speciation and dispersal (Foley and Lahr 1997; Lahr and Foley 1998,200 I). Recent research in the Kapthurin Formation of Kenya, which preserves a welldated sequence ofAcheulian and MSA sites, is therefore relevant to this discussion.

logical word is the end Of the IMg-livad A&&

adaptations that drove this change, as well as begin

Survey Objectives and Results FUM investigations conducted in the southern

Kapthurin Formation were directed at the recovery

ing localities, as well as detailed tephrostratigraphic obmt ioas of the Bedded Tamember. Walkover survey of known exposures lasted f h m 8 May- 1 June 2001, followed by test trenching at GnJh-75 and

full-scale block excavation, with some 52-m2 excavated in 2001. 'lbnty sites, primarily surface

sites re-investigated (Table 1 and Figure 1). Tht

Of a d d i t i d archae~logical sitn and fossil ~ ~ l l e c t -

Koimilot (GRm-74). Koimilot WBS later Chosen for

scattm,werediscovatd~gthes\pvey,withfour

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NYAMEAKUAU No. 57Jum 2002

Figure 1: Archaeological and fossil sites hm the southern Kapthrvin Famatian. Included arc archaeological andpelaeOntologicalsites~the2001 survcy(seeTable 1). Localities26-28wereinitialiyreportedbyMcBrtarty ef 2. I ,sw, plant

7

SASES c4mtealt Wgraphy

Galh-13 artifactsandfauna K 4

-12 a r t i f a c t s a n d h K3

GnJh-64 mtifacts K4

GnJh-65 artifactsandf;auna K3

AtQibUtiOn

Acheulian-MSA

Acheulw

?ssngoan-MsA

Actaculh

~~~ ~

artifactsandfauna

artifacts

artifacts

artifacts

artifacts

artifacts

-

K3

K3

K3 and K4

K3

K3

K4

artifactssndhuna

artifactsandfauna

artifactsandfauna

fauna

K3 ?MSA

K3 Acheulian

K4 Achedim

K3 NIA

15

16

17

18

19

Loc. 112

Loc. 113

Loc. 114

Loc. 115

Loc. 116

artifacts

artifacts

idfacts

artifbasandfauna

artifactsandhuna

artifiicts

K3 Acheulian

K4 Acheulian

K4 Acheulian

K4? MSA

K4 MSA

K4 MSA

21

22

23

24

Koimilot (Loc. 118)

Loc. 119

N y ogonyek

Logumkum artifacts and fauna Ilosowuani Fm. M S A - R m t

Table 1: Southern Kapthurin FcUmation s i t s fomd during 2001 s u r ~ y

Site Name

Loc. 39

Loc. 40

Loc. 100

Loc. 101

Loc. 102 artifactsandfauna I K3 I Acheulian ~

Lac. 103

Loc. 104

Acheulian

Indctuminate

?Acheulian

Indeterminate

Acheulian-MSA

Acheulian

Loc. 105 GnJh-69

GnJh-70

GnJh-71

1 9 Loc. 106

Loc. 107

I l 1

~~

Loc. 108 I

12 Loc. 109 Grim-72 fa\pna K3 NIA

Loc. 110 -73

I 14 ~LQc. 111

Galh-8

GoJh-9

GoJh-10

GnJh-76

Go&- 1 1

GnJh-75

GnJh-74

GnJh-77

artifactsandhum I K4Moloccnesed I MSA-LSA GoJh- 1

GoJi-7

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NYAME AKUMA No. 57 June 2002

approximate spatial extent of each site was deter- mined in the field, as was sedimentary and stratigraphic context. A Magellan 3 IS GPS unit pro- vided precise locational data, and - usell for attribution of a site to period or industxy were col- lected. Artifacts and fossils are presently housed at the Archaeology Division of the National Museums of Kenya (NMK) in Nairobi.

Southern Kapthurin Formation Paleontology and Archaeology

The 2001 survey was successll in identifl- ing a suite of previously unknown paleontological and archaeological localities h m southem exposum of the Kapthurin Formation. Sites o c d within alluvial and lacustrine sediments, in multiple temp raYstratigraphic contexts. Although in situ fossils were observed and recovered h m multiple locali- ties, fossil fauna are generally neither abundant nor well preserved in the southern Kapthurin Formation. Plant fossils are occasionally found, at times in growth position, within layers of &-fall tuf€(Tallon 1976, personal observation). Two tephra layers rich in both grass and leaf impressions bracket the excavations at Koimilot.

Archaeological variability in the southern Kapthurin Formation is comparable to that found north of the Ndau River (e.g. Cornelissen 1992; McBrearty et ul. 1996; McBrearty 1999). Sites at- tributable to the Acheulian Industrial Complex are well represented by handaxes and cleavers, produced from a range of fine-to-coarse grained lavas. These implements were prodyced from side and end-struck flakes, from cobbles (GoJh-12) and the Kombewa method (Gnlh-76). A large Levallois flake, similar to those used for handaxe production at LHA (Leakqr er a1 1969) was also recovered in situ from within the Bedded Tuff at GnJh-62. Picks, found in the Acheulian but often considered characteristic of the Sangoan, were found in situ at GnJh-66, and have been reported fiom elsewhere in the Kapthurin For- mation (Cornelissen 1995). Cores include a variety of single and multiple platform, discoidal and rare Levallois types.

containing rarc points and Levallois cores at GoJh- 13 and Grim-71, and more extensive s\irface scatters at Logumkum (GoJi-7), Nyogonyek (GoJh-1), and Koimilot (GnJh-74). Artifacts from Logumkum (Logumkum TV of Farrand et ul. 1976) include Lcvalloisanddiscoidalcores,Le~loiSpointSasweU as scrapers and bifacial points made on Levallois flakes; rare artiEacts are of obsidian. These lie on an up-fiiultcd sedimentary sequence of lacustrine sedi- ment and W, assigned to the Ilosuowani Foxmation (Tiercelin and Vicens 1987; Le Turdu et aZ. 1995). Nyogonyek is a large eroded area containing multi- ple dense patches of artifacts, many of them typo- logically Later Stone Age, first reported by Fanand et ul. (1976). An artifact concentration discovered in 2001 consists ofnumerous Levallois cores, flakes and points, produced by lineal as well as convergent andunipolarrecurrentmethods(cfB& 1994). The artifacts are apparently within down-faulted sediments of a lacustrine h i e s of the Middle Silts and Gravels member (Tallon 1976; Fanand et ul. 1976; McBrearty 1999).

Excavation at Koimilot (GnJh-74) recovered two stratified MSA assemblages (Tryon and McBrearty 2002b) (Figures 3 and 4). Over 2000 ar- tifacts were movered from the 36-m2 excavation at Locus 1, the stratigraphically lower of the two as- semblages. Artifacts occur in a -IO-cm-thick hori- zon within fine-grained overbank sediments, with refitting sets h m within the excavated area as well as between the excavation and surface finds. Is+ lated teeth and tooth hgments comprise the recov- ered fauna The lithic assemblage consists of casu- ally flaked large cobbles, as well as a dense debitage concentration and associated centripetally flaked cores that apparently reflect a Levallois mode of flake production. Retouched pieces are rare. Locus 2 is adjacent to and stratigraphically higher than Locus 1 (Figures 3 , 4 and 6). The 12-m2 excavation recov- ered -150 artifacts from within a 10-an-thick zone fiom five of the excavated meters. Artifacts are as- sociated with fine-to-coarse sands, and include large (max. length 2 10 cm) Levallois points and elongated flakes, a centripetally flaked Levallois core, a blade core and ochre. Future research will systematically explore differences observed between Locus 1 and

'

Middle Stone Age sites from the southern Kapthurin Formation include sparse surface scatters

Locus 2 at Koimilot, as well as comparison of these assemblages with other sites, seeking to document

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NYAMEAKUM No. 57June 2002

and explain temporal or functional variability within the MSA.

Tephrostratigraphy Multiple t e p h samples were collected from

measured stratigraphic sections, and energy-disper- sive electron microprobe (Em) analysis is currently in progress, using equipment housed at the mine Geology Laboratories, Yale University. Preliminary field stratigraphic, petrographic and EMP analysis of glass geochemistry suggest that tuffs underlying the archaeological deposits at Koimilot are compa- rable to the ‘hpper basaltic” portions of the Bedded Tuff identified by Tryon and McBrearty (2002a). Im- portantly, this makes Locus 1 and Locus 2 at Koimilo?, both assigned to the MSA, the youngest excavated assemblages thus far from the Kapthurin Formation, as all other known sites underlie these ”upper basal- tic” Bedded Tuff deposits. Additional tephra at Koimilot include deposits not previously observed. These include the “Koimilot tuff” and basaltic tuf€ deposits that are not part of the established tephrosequence of the Bedded Tuff member. The “Koimilot tuff serves as a local marker bed, and is a fine-grained dacitic tuff which likely has a distant source outside the Baringo basin, offering the poten- tial for long distance correlation such as has been achieved with deposits in the Lake Turkana basin (e.g. Brown 1994; Feibel 1999).

Additional preliminary EMP analyses have been undertaken for tephra at Logumkum, Nyogonyek and (30%-12. Ash deposits at Logumkum are unlike any presently known from the Kapthurin Formation, while those at Nyogonyek and GoJh-12 are tentatively identified as Bedded Tuff, with con- firmation pending subsequent laboratory reanalysis as well as the collection of additional field samples.

Conclusions The end of the Acheulian is a major Middle

Pleistocene archaeological event. The highly re- solved stratigraphic record of the Kapthurin Forma- tion provides the opportunity to examine basic is- sues of the chronology of the Acheulian to Middle Stone Age transition (Deino and McBrearty 2002; Tryon and McBrearty 2002a). Construction and com- parison of local sequences of archaeological and paleoecological change, such as those from the

Kqthurin Formation audKalambo Falls (Clark 200 I) is a necessary step for the formulation of hypotheses regarding hominid behavioral adaptations during and subsequent to the Acheulian-MSA transition. The additional sites discovered during the survey of the southern Kapthurin Formation, as well as excavation at Koimilot, expand both the site sample, as well as the time span of observable archaeological change in the Baringo basin.

Acknowledgements Work in the southern Kapthurin Formation was

conducted under a research permit &om the Govern- ment of the Republic of Kenya (permit no. MOEST 13/00 1 /3OC 229) and an exploration and excavation license h m the Minister for Heritage and Sports. Funding was provided by the L. S. B. Leakey Foun- dation, the Wcnner-Gren Foundation for Anthropo- logical Research, Inc., the Bill Bishop Memorial Trust, and the National Science Foundation (BCS- 0 I 18345). The success of the present investigation is due in part to my entire field crew, but most espe- cially Boniface Kimeu, Mustah Kirika Waweru and Simon Katkya. Sally McBrearty and Andrew Hill provided guidance and both material and moral sup- port. Lastly, I thank my parents and Rhonda Kauffman for their kindness and patience.

References

B&da, E. 1994 Le concept Levallois: VariabilitP des

mdthodes. Paris: CNRS Editions.

Brown, F. H. 1994 Development of Pliocene and Pleistocene

chronology of the Turkana Basin, East Af- rica, and its relation to other sites. In R. S. Cormccini and R. L. Ciochon, editors, In- tegrative Paths to the Present: Paleoanthropological Advances in Honor ofF: Clark Howell. Englewd Cliffs, NJ: Prentice Hall, pp.285-3 12.

10

WAME AKlJMA No. 57Junc 2002

Clark, J. D. 1982

1988

1994

2001

The transition from Lower to Middle Palaeolithic in the African continent. In A. Ron- &or, The lhn.&ion From Lower to MiaWe Palaeolithic and the Origin of Modern Man, oxford: B A R . International Series 151: 235-255. The Middle Stone Age of East Afiica and the beginninss of regional identity. J w - nal of World Prehistory 2: 235-305.

The Acheulian Industrid Complex in Af- ricaandelsewhcre. InR S. Comccini and R. L. Ciochon, editors, Integrative Paths to the Past: Paleoanthrvpological Advances in Honor of E Clark Howell. Englewod Clia, NJ: Prentice Hall, pp. 45 1470. Kalambo Falls Prehistoric Site, Vol. 3. The Earlier Cultum: MiaHe and Earlier Bone Age. Cambridge: Cambridge University Press.

Cornelissen, E.

1992 Site GnnE.17 and Its Implications for the Archaeology of the Midde Kqthurin For- mation, Baringo, Kenya. Tervuren: Musk Royale de 1'Afrque Centrale, Annales, Sci- ences Humaines 133.

1995 Indications du post-Acheulh (Sangoen) dam* la formation Kapthurin, Baringo, Kenya. L 'Anthropologie 99: 55-73.

Cornelissen, E., A. Boven, A. Dabi, J. Hus, K. Ju Yong, E. Keppens, R. Langohr, J. Moeymns, P. Pasteels, M. Pieters, H. Uytterschaut, F. Van Noten, and H. Workineh

1990 The Kapthurin Formation revisited. Afri- can Archaeological Review 8: 23-76.

Deacon, H. J. and J. Deacon

1999 Human Beginnings in South Africa: Uncov- ering the Secrets of the Bone Age. Cape Town: David Philip.

Demo, A. and S. McBrearty

2002 s9ArPAr dating of the Kapthurin Fomation, Baringo, Kenya. Journal of Human Evolu- tion 42: 185-2 10.

Fanand, W. R, R W. Reddmg, M. H. Wolpoff and H. T. Wright

1976 An Archaeological Investigation on the Loboi Plain, Baringo District, Kenya. Ann Arbor: Muse~m of Anthropol~g~, UniVer- sity of Michigan Technical Reports No. 4.

.

Feibel, C. S.

1999 Tephrostratigraphy and geological context in pal~thropology. Evolutionmy A n t h p ~ l o g ~ 8: 87-100.

Foley, R. A. and M. M. Lahr 1997 Mode 3 technologies and the evolution of

modern humans. Cambridge Archaeologi- cal J& 7: 3-36.

Hill, A.

2002 Paleoanthroplogical research in the Tugen Hills, Kenya. Journal of Human Evolution 42: 1-10.

Howell, F. C.

1999 Paleo-demes, species clades, and extinctions in the Pleistocene hominin record. Journal of Anthropological Re- search 55: 191-243.

Isaac, G L.

1982 The earliest archaeological traces. In J. D. Clark, editor, Cambridge Histoiy ofAfica, Vol. I , pp. 157-247. Cambridge: Cambridge University Press.

I ?

NYAMEAKUM Mo. 57June 2002

Lahr, M. M. and R Foley

1998 Towardsatheoryofmodemhumanorigins: Geography, demography, and diversity m

cal Anthropoloog~ 4 1 : 137-1 76.

Mode 3, Homo klmei, and the pattern of human evolution m tht Middle Pleistocene. In I;. Barham and K. Robson-Brown, editors, Human Roors: Afiica and Asia in the Mi&le Pleistocene. B~istol, England: Westan Academic and Specialist Press. pp. 23-40.

m t h- evolution. Y e d o o k q P W -

2001

Le TWU, C., C. C~ussement, J.-J. Tier~elin, R W. Renauf J. Rolet, J.-P. Richut, J.-P. Xavier and D. Coquelet

1995 Rift basin structure and depositional patterns interpreted using a 3D remote sensingapproach:TheBaringoandBogoria basins, Central K e ~ y a R i q EastAfiica. Bull. Cen!res Rech Erplol: -Prod EIf Aquitaine 19: 1-37.

Leakey,M.,P.V.Tobias,J.E.Martynaud RE.F.

1969 An Acheulian indusw with prepared core technique and the discovery of a contem- porary hominid mandible at Lake Baringo, Kenya. Proceedings of the Prehistoric Su- ciety 3: 48-76.

Leakey

Martyn, J. E.

1969 The geological history of the country be- tween Lake Baringo and the Kerio River. Baringo District, Kenya Ph.D. Dissatation. University of London.

McBrearty, S.

1999 Archaeology of the Kiipthurin Formation. In P. Andmw and P. Banham. editors, Lare Cenozoic Environments and Hominid Evolution: a Tribute to Bill Bishop. London: Geological Society, pp. 143-156.

The Middle Pleistocene of east Afiica. In L. Barham and K. Robson-Brown, editors, Human Roots: Afika and Asia in the MWie Pleistocem. Bristol: Western

2001

Academic and Spe~ialist Press, p ~ . 8 1-98.

McBmrty, S., L. C. Bishop and J. D. Kingston

1996 Variability m traces of Middle Pleistocene hominid bcbavior m the Kapthurin Fonna- tion, Baringo, Kenya. Joranol of Human Evolution 3 0 563-580.

McBrearty, S. and A. S. Brooks

2000 Iht ~ v o l u t i ~ a tbat wasn’t: A mrised inter- pretation of the origin of modern human behavior. Journal of Human Evolution 39: 453-563.

Stringer, C. B. and P. Andrcws

1988 Genetic and fossil evidence for the origin of modern humans. Science 239: 1263- 1268.

Tallon. P. W. J.

1976 The stratigraphy, palaeoenvironments and geomorphology of the Pleistocene Kapthurin Formation, Kenya. Ph.D. Disser- tation, Queen Mary College, London.

Geological setting of the hominid fossils and Acheulian artifitcts f h n the Kapthurin For- mation, Baringo District, Kenya. In W. W. Bishop, editor, Geological Background to Fossil Man Edinburgh: Scottish Academic

1978

Press, p ~ . 361-373.

NYAMEAKUMA No. 57June 2002

Tiercelin, J.-J. and A Vmcea~, editors 1987 Le --Graben de Baringo-Bogoria, Rift 1994 Africa in the period of Homo sapiens

hydrologique &Swimentape - .0d..e?m?S J. DeLaetetoL, edbs, HistorytfHaman- Rech Ihplm-Pt6d Ey-Aguitpine 11 ~249- a@, Vol. 1: &history adthe Beginnings 250. ofCiyilizcrtio. New Yo& Routledge and

WeadoPZF.,A.ECloseandRSchild

Gregory, Kenya: 30,000 80s d'histoire neanderthal~isdcontempararies.Ins.

UNESCO, p ~ . 117-135.

Tryon, C. A. and S. McBmuIy

2002a

2002b

Wood, B. T e p M g r a p h y and the Acheulian to Middle Stone Age transition. Jotanal of 1999 Plio-PieistoCenehomininsfiromthcBaringo Human Evolution 42: 21 1-235. Region, Kenya. In P. Andrews and P.

The Middle Stone Age of the southern Kapthlrrin Formation. JapM.J of Hunrun Evolution 42: A37.

Banbam, editors, Late Cenozoic Envkn- mem and Human Evolution: A Tribute to BiU 0ishop. London: Geological Society, pp. 113-122.

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